1. Technical Field
The present invention relates to a copy machine that reads an image of a document and makes a copy of the document, and a non-transitory computer readable recording medium that is stored with a control program for the copy machine.
2. Description of Related Art
In recent years, multifunction devices (Multi-Function Peripheral: MFP) having the functions of a copier, printer, image scanner, facsimile and so on, are gaining popularity. An MFP is provided with an automatic document transport device (Auto Document Feeder: ADF) that feeds a document to an image reading unit for reading an image of the document, and can read a plurality of documents in a row.
When copying processes of a document are performed by an MFP having an ADF, normally, the document is set in the ADF such that the short-side direction of the document matches the transport direction of the document, and the document is fed from the ADF to an image reading unit by LEF (Long Edge Feed). An image of the document fed by LEF is read by a line sensor that is provided to extend in a direction orthogonal to the transport direction of the document, where the long-side direction of the document is in line with the reading main scan direction and the short-side direction of the document is in line with the reading sub-scan direction. Then, an image, which is based on image data acquired by the line sensor by reading the image of the document, is formed on a sheet of paper that is fed from a paper feed tray to an image forming unit by LEF. The image forming unit has an optical unit that is formed with a laser oscillator, a polygon mirror and so on, and forms an image on the sheet of paper fed by LEF, such that the long-side direction of the sheet is in line with the writing main scan direction and the short-side direction is in line with the writing sub-scan direction.
According to this configuration, the time required for the reading process of the document becomes short compared to a case where a document is fed from an ADF by SEF (Short Edge Feed) and an image of the document is read such that the long-side direction of the document is in line with the reading sub-scan direction. Also, the time required for the image forming process on paper becomes short compared to a case where paper is fed from a paper feed tray to an image forming unit by SEF and an image is formed such that the long-side direction of paper is in line with the writing sub-scan direction. In addition, since the orientation of image data acquired by reading a document and the orientation of paper match, it is not necessary to rotate the orientation of image data through 90 degrees, and the time required for copying processes can be minimized.
However, there are ADFs that can set a document only in the orientation of SEF and that can feed a document to an image reading unit only by SEF. Also, even if an ADF is able to set a document in either direction of LEF/SEF, depending on the users, cases might occur where a document is set in the direction of SEF and the document is fed to an image reading unit by SEF.
In the event a document is fed by SEF and an image of the document is read such that the long-side direction of the document is in line with the reading sub-scan direction, feeding paper by SEF may make it unnecessary to rotate image data and consequently make the time required for copying processes short, or feeding paper by LEF may make the time required for the image forming process short and consequently make the time required for copying processes short. Consequently, in the event a document is fed by SEF and an image of the document is read such that the long-side direction of the document is in line with the reading sub-scan direction, it is preferable to appropriately switch the feeding direction of paper on which an image is going to be formed and shorten the time required for copying processes.
Note that Unexamined Japanese Patent Publication No. H09-018690 discloses a technology for, in copying processes of a document, feeding paper in an orientation that matches the orientation of a document from a paper feed tray, and forming an image. However, although according to this technology it is not necessary to rotate image data, when a document is fed by SEF, the time required for copying processes does not always become short.
Also, Unexamined Japanese Patent Publication No. 2001-322326 discloses a technology for, in a printing process of forming an image based on print data on paper, selecting the paper feeding direction to give the shorter printing time, by considering the difference in the time required for an image forming process on paper that is fed by LEF/SEF, and the time required for the process of rotating image data. However, this technology is specific to a printing process and does not take into account reading of an image of a document by an image reading unit.